Bacteria associated with acidic and neutral pH rock drainage inthe wet-dry tropics of northern Australia

摘要

Rum Jungle, Mt Todd and McArthur River mine sites are located in the NorthernTerritory, Australia. Rum Jungle and Mt Todd are acidic sites while McArthurRiver mine has neutral pH drainage. While the role of microorganisms in acidrock drainage (ARD) is well understood in some parts of the world, there is verylittle known about ARD microbiology in the wet-dry tropics with its extremeseasonal patterns. We examined the microbial populations and metals in acidicand neutral pH drainage, tailings and waste rock. The hypervariable V6 region ofthe bacterial 16S ribosomal RNA genes was amplified and sequenced. Themajority of bacterial V6 sequences isolated from samples could not be classified.Of the classified bacteria, Enterobacteriales, Actinobacteria, Burkholderiales andChromatiales were most frequently identified in drainage, waste rock dump andtailings samples. The bacterial population changed with season and there was aweak correlation between the physicochemistry of WRD and tailings, and thebacterial community. Only two iron oxidizing Acidithiobacillales were identifiedat the sites. Actinobacteria were more frequently identified and members of thisclass can be iron oxidizers so these bacteria may contribute to iron cycling inacidic and neutral pH drainage of northern Australian.